InvalidOperationException when calling SaveChanges in .NET Entity framework

Question

I\'m trying to learn how to use the Entity framework but I\'ve hit an issue I can\'t solve. What I\'m doing is that I\'m walking through a list of Movies that I have and ins

Answer 1

This exception seems to tell you that you have equal values in severals rows in the Id column, which is supposed to only have unique values, because it's a key column. Entity Framework can handle such columns in two ways: either you (the Client) generates unique values, or the Server generates unique values. In your case it seems logical to allow the Server to generate autoincremented keys.

Do you have the StoreGeneratedPattern key set for the Id column in your SSDL file?

Here is an example from this blogpost: